Apparatus for cooling air by the evaporation of liquids



y 1949- F. c. SIMONDS 2,470,657

" APPARATUS FOR COOLING AIR BY THE EVAPORATION OF LIQUIDS Filed March 21, 1947 3 Sheets-Sheet 1 INVENTOR FRANK C. SIMONDS 59 7221s ail'or'neya WWGW May 17, 1949. F. c. SIMONDS 2,470,657

APPARATUS FOR COOLING'AIR BY THE EVAPORATION 0F LIQUIDS Filed March 21, 1947 5 Sheets-Sheet 2 INVENTOR FRANK C. SIMONDS y 722's atlarneys May 17, 1949. F. c. SIMONDS APPARATUS FOR COOLING AIR BY THE EVAPORATION OF LIQUIDS Filed March 21, 1947 3 Sheets-Sheet 3 INVENTOR FRANK C. SIMONDS v Zyhz's attarneya, WW8, y/azz/zm Patented May 17, 1949 UNITED STATES PATENT OFFICE APPARATUS FOR COOLING AIR BY THE EVAPORATION OF LIQUIDS 6 Claims.

This invention relates to a cooling system, and more particularly a system for cooling a circulated fluid which carries heat from a heated article or chamber. The invention is especially useful in connection with air-cooling electromagnetic apparatus used in turbo-electric-driven ships, to which use, however, it is not restricted.

One object of the invention is to prevent a secondary cooling fluid from entering a primary cooling fluid in a heat exchanger. A further object is the provision of a simple and eflicient cooling system which may be effectively operated from available apparatus. Other objects and advantages of the invention will be apparent from the present specification.

The invention is shown by way of illustration in the accompanying drawings, in which Fig. l is a diagrammatic view of one form of the invention as used for cooling electro-magnetic apparatus;

Fig. 2 is a diagrammatic view of a slightly different form of the invention also applied to electro-magnetic apparatus;

Fig. 3 is a diagrammatic view of a different form of the invention applied to air conditioning apparatus; and

Fig, 4 is a diagrammatic view of still a different form of the invention, also applied to air conditioning apparatus.

Many installations exist in which a fluid is used to remove heat from a heating point and is then circulated through a cooler, where heat is removed therefrom, whence it is recirculated past the heating point. Cycles of this nature are common in air conditioning systems and on ships where weather may prevent employment of fresh air for cooling. Separate refrigerating plants for cooling the recirculated cooling fluid require expensive apparatus and a considerable consumption of power. Furthermore, leakage of the secondary cooling fluid, which cools the cooler, into the primary cooling fluid, which is circulated through the cooler to give up its heat therein, may produce undesirable results. For example, where air is used to cool electro-rnagnetic apparatus as the motors and generators of turboelectric-driven ships, the heated air coming from the housings of such electro-magnetic units customarily passes through an air cooler having water tubes through which sea water is pumped. Corrosion of these water tubes by the sea water results in leakage thereof into the cooled air and deposit of moisture and salt on the electro-magnetic parts. Such deposits may clog, corrode or even burnout the electrical apparatus,

I have found that, where power units which employ condensers are available, it is possible to cool the primary cooling fluid without employing expensive apparatus, and without large consumption of power; and I have found it possible at the same time to avoid leakage of the secondary into the primary cooling fluid. Essentially, the vacuum of a vacuum condenser is applied to a heat exchanger to cool the primary cooling fluid which is recirculated past the heating point and through the heat exchanger.

The embodiment of the invention shown in'- Fig. 1 illustrates the application of the invention to an air-cooling system for electro-magnetic apparatus, as a motor or generator of a turbo-electric-driven ship. This illustration includes an electro-magnetic apparatus l0 (which may be a motor or a generator) the casing of which comprises a sealed chamber containing the parts to be cooled. A closed conduit system is connected across the chamber. Thus, a heated air conduit H connects the apparatus II] to a primary cooling fluid passage I2 in a heat exchanger !3, and a cooled air conduit I4 connects the primary cooling fluid passage again to the apparatus. The air, or primary cooling fluid may be circulated through the apparatus in any known or convenient manner, as by a fan (not shown) in the casing of the electro-magnetic apparatus. If the heat exchanger is properly cooled, therefore, heat will be abstracted from the air brought thereto by the heated air conduit H, and the cooled air will be carried therefrom to the eiectro-magnetic apparatus by the cooled air conduit M.

The heat exchanger i3 is cooled by evaporating a liquid therein. Thus, the heat exchanger has a secondary cooling fluid passage sealed from and in heat exchanging relationship with the primary cooling fluid passage l2. In the embodiment illustrated, the secondary cooling fluid passage comprises a water box or receiving header a vacuum chamber or discharge header l6, and a number of tubes l1 extending across the primary cooling fluid passage l2 and connecting the headers l5 and It. A secondary cooling fluid, passing across the primary cooling fluid passage l2 through the tubes U, will therefore abstract heat from the primary cooling fluid, if the temperature of the former is lower than that of the latter.

The temperature of the secondary cooling fluid in the heat exchanger is maintained at a relatively low point by the action of a condenser eludes the secondary cooling fluid passage (headers and tubes) of the heat exchanger.- Thus a pipe 23 is connected, as at 24, to the feed water line 22 adjacent the pump 2|, and is connected";

at its other end to the receiving header in the heat exchanger. A valve in the pipe 23,'ad.iacent. its connection with the feed Water line, permits condensate from the condenser, under pressure of the pump 2| ,'to enter'the-pipe-23 or excludes the condensate" therefrom." The closed pipe systemthrough the condenser" and theheat exchanger is completedbyja pipe--26, coupled. .to the discharge, header 16 *orthe heat exchanger,:and joined 'to an extension pipe 21', which is in turn connected to *a'ieed 'pipe 28 coupled .to the condenser; A va1ve29contr'ols the flow throughthe extension pipe21, and a valve .in the feed pipe 28 permits or prevents fluid thereinfromentering the condenser |8.-

Operation of the apparatus so far described will be readily understood' The valves 25;29 and-'30 being open, condensate :fromthe-condenseri'l8 enters the pipe 23 under pressure or the pump 2 I and is sprayed into the waterbox or receiving header I5 of the heat exchanger I3. At the same time, vacuumfrom the condenser is applied to the vacuumchamber or discharged header l6 "of the' heat exchanger from theconde'nser I8 through thefeed pipe 28;the extension pipe 21' and the pipe- 26. Accordingly, the condensate sprayed-into the-receiving header is boiled or evaporated," passes through the tubes I! 'to the vacuum chamber or" discharge header whence it returns to the condenser as water vapor As the condensate boils 'or evaporates under the vacuum of the 'condenser, it absorbs itsheat. of vaporization from the :heat exchanger and the air orprimary cooling fluid" circulated therethrough; thereby cooling theai-r or primary cooling fluid.-

Without wishing to be limited to 'any -quantita-' tive statements, and without assertingitheacomplete accuracy thereof, the followingwill'give anidea 'of'the-cooling action of the "apparatus. The condenser may be considered as being under azvacuumof 28 inches of mercury and at a tem perature of 100*degrees Fahrenheit. The condensate'in the condenser;having given up its latentheat of condensation to the'cooling water of the condenser, and'being. unable to regain it because-of the-continued removal of-heatby the cooling water; remains in liquid form in the. condenser. Furthermora-the pump 2| delivers the condensate to the heat exchanger at substantially IOOcdegrees Fahrenheit. Here, again subjected tothevacuum of the-condenser,..the condensate is able :to: gain .its latentheatof. vaporization from theprimaryycoolingufiuid. passing through the heat exchanger. Thereupon the condensate evaporates andwbecomesa vapor, .at 100 degrees Fahrenheit,.in..which.lf0rm.it returns to the condenser Cooling ,air, leaving the. ele'ctro-magnetic apparatus at, say 130degrees Fahrenheit may 4 therefore be cooled in the heat exchanger to 100 degrees Fahrenheit,

If it is desired to reduce the temperature of the primary cooling fluid still further as it passes through the heat exchanger, one way of doing so is to apply a refrigerating coil 3| to the pipe 23 between the pump 2| and the receiving header l5.

Anotherrmeans for reducing still further the temperature of the primary cooling fluid is illustrated in Fig. 1. The pipe 26 which is coupled to the discharge header I6 is shown as continued beyond thezpoint at. which it is joined to the extension 'pipe27 to connect with an ejector 32.

.A.ivalve 33.-serves to permit or shut ofi flow through the pipe 26 to the ejector. The ejector is operated'imwell k-nown manner by steam from a pipe 34, and discharges into the condenser through the feed pipe 28. -A valve 35 serves to shut off the ejector. Thus, with the extension pipe shut off? by the "valve -29 and the valves 33 and"35-bpen,' the-'ejector will apply vacuum to the header I I6 inadditionto that ofthe condenser: It'has' been-found that an' additional inchof-vacuummay be applied-by the ejector to the secondary cooling fluid passage through the heat exchanger. Thus the ejector 32 may bring thevacuum in'the heat exchangerddwn to 29 inches of mercury; and the-resultant boiling or "evaporation of the condensate therein will reduce-its temperature to substantially degrees Fahrenheit. Consequently if air at 130' degrees Fahrenheit enters the heat exchanger from the el'ectro magneti'c' apparatus H],- the condensate will absorb its heat of vaporization therefrom; and it'has been*found possible to reduce the temperature 'ofthe cooled air from 130 degrees to degrees Fahrenheit in the heat exchanger.

In'this" connection it"is to be'noted that only a small. part of the condensate from the con= de'nseris used inithe heat exchanger 13. Furthermore; the condensate coming fromthe 'con'-' denser! is fresh waterand'does'not tend .to corrode :the "tubesi'l'l .in" the heat exchanger 'or to enter the primary cooling 'fiuid.

Inthe .embodiment of the invention which; is illustrated "in Fig; 2 "a slightly" different 'form of the 'invention'is shown wherein the ejector 32 is continually. used to applya vacuum to the heat exchanger I3.. Furthermore; the ejector dischargeslinto the condenser through an intercooler 36,?throughwhich'the feed water line 22 passes in a coil'3l'.'i Thus the heated vapor from the heat "exchanger l3 "filling the inter-cooler 36on.its. way .to' the condenser I8 'gives up some ofv its heat to the feed water. A pipe- 38 carries the condensate from the inter-cooler to the condenser..

In Fig. 3 the invention is shown in its application toan air conditioning system which. is located at a distance from the coolingmachinery. Here a colu'mnof heated air is1coo1ed .bya primarycooling fluidwhich is circulated .through theair'coIumn and through. a h'eat exchanger, where it is cooled. The heat exchanger is cooled by boiling..0r.evaporation under the vacuumcf the usual condenser 18 and the vacuum induced by air ejector- 32*.

As illustrated in Fig.3, the heated airto be cooled is carried by,.an intake conduit 39 into .a casing) which it leaves bya discharge-conduit M. The primary, cooling fluid is circulated through'the casing in a coil 42,which'is connected by a supply'gconduit 14 and-a return. conduit 1 I with a heatexchanger II-Wwhere the primary cooling fluid is cooled. A primary cooling fluid pump 43 circulates the primary cooling fluid between the casing 40 and the heat exchanger I3 Because the primary cooling fluid functions at a distance from the heat exchanger, water is used as the primary cooling fluid. For a given pipe diameter water will carry a larger number of B. t. u.s than air.

The heat exchanger I3 is of a different type from the heat exchanger l3 which has been described. The heat exchanger l3 is an ordinary tank into which the heated primary cooling fluid is carried by the return conduit ll and from which the cooled primary cooling fluid is carried by the supply conduit I4 To cool the heat exchanger l3 condensate from the condenser 18 is carried from the feed water line 22 into the tank by a make up water pipe 23 having a valve 25 therein; and the vacuum of the condenser l8 augmented by the vacuum induced by the ejector 32 is applied to the topof the tank by a pipe 26. The primary and secondary cooling fluids are comingled in this heat exchanger.

Thus, cooling liquid at the temperature of the condenser is fed into the heat exchanger and the vacuum of the condenser plus the induced vacuum of the ejector boils or evaporates the contents of the tank whereby the entire body of liquid is cooled. Heated cooling liquid from the return conduit Il is therefore cooled by the body of water with which it mixes in the tank. Cooled water from the body of water in the tank is withdrawn by the primary cooling fluid pump 43 and sent through the supply conduit l4 into the coil 42.

In this apparatus which has just been described, the cooling process is, broadly viewed, the same as those disclosed in Figs. 1 and 2. The heated cooling fluid is passed through a heat exchanger which is cooled by evaporation of a liquid therein.

Fig. 4 shows an application of the invention to an air conditioning system which is located nearer to the cooling machinery than that illustrated in Fig. 3. In this embodiment the air which is being conditioned is passed through a heat exchanger l3 which is very similar to the heat exchanger 13 shown in Figs. 1 and 2. The heat exchanger is vacuum-cooled as is that shown in Figs. 1 and 2.

In the embodiment shown in Fig. 4, the heat exchanger l3 has an air passage I2 therein to which a warm air pipe 44 carries air to be cooled. A cool air pipe 45 carries the cooled air from the heat exchanger T3 The heat exchanger 13* is constructed and operated like the heat exchanger I3 shown in Figs. 1 and 2. Thus a passage like the secondary cooling fluid passage in the previously described heat exchanger is provided in the heat exchanger l3 and is sealed from and in heat exchange relationship with the air passage 12 therein. This passage comprises a water box or receiving header IS, a vacuum chamber or discharge header I6, and a number of tubes I1 extending across the air passage l2 and connecting the headers l5 and I6.

The heat exchanger is connected to the condenser l8 in the same manner as has been described in connection with the heat exchanger shown in Fig. 1. Thus a. pipe 23 is connected as at 24 to the feed water line 22 adjacent the pump 2|, and is connected at its other end to the receiving header 15. A valve 25 in the pipe 23 permits condensate from the condenser, under pressure of the pump 2 l, to pass through the pipe 23 or prevents its passage therethrough. A pipe 26 coupled to the discharge header [6 connects the heat exchanger to an ejector 32 similar to that shown in the previously described embodiments of the invention. A valve 33 serves to permit or shut off flow through the pipe 26 to the ejector. The ejector is operated by steam from a pipe 34 controlled by a valve 35*, and discharges into the condenser I8 through a pipe 28.

The heat exchanger l3 is cooled in the manner which has already been described in connection with the similar heat exchangers.

The heat exchanger [3 may be easily adapted to warming instead of cooling the air which passes through the air passage [2 therein. Accordingly, a steam pipe t5, controlled by a valve 41 may serve to admit steam to the receiving header l5, and traps it and d9 may be connected to the bottoms of the headers 15 and It respectively. When the air is being warmed the valves 25 33 and 35 in the cooling system are, of course, closed.

From the foregoing it will be apparent that the invention provides a simple and efflcient cooling system which may be effectively operated from an available condenser or ejector, or both. Furthermore, secondary cooling fluid, which is under vacuum, cannot enter the primary cooling fluid, and since the secondary cooling fluid is fresh water it will not corrode the pipes of the heat exchanger.

The particular forms of the invention here described and illustrated in the accompanying drawings are presented merely as examples of how the invention may be applied. Other forms, embodiments and applications of the invention, coming within the proper scope of the appended claims, will readily suggest themselves to those skilled in the art.

I claim:

1. In apparatus for cooling a fluid, a heat exchanger having primary and secondary cooling fluid passages therein in fluid sealed and heat exchange relationship with respect to each other, a primary cooling fluid conduit system connected to said primary cooling fluid passages of the heat exchanger, an exhaust steam line, a condenser operating under vacuum and connected to said exhaust steam line to receive steam therefrom and condense the same, a pipe system for introducing at least a portion of said condensate from said condenser into one end of the secondary cooling fluid passages of said heat exchanger, and a second pipe system connecting the vacuum side of said condenser to the other end of said secondary fluid passages of the heat exchanger to reduce the pressure therein and vaporize the condensate thereby cooling the primary cooling fluid passing through said heat exchanger.

2. In apparatus for cooling 2. fluid, a heat exchanger having primary and secondary cooling fluid passages therein in fluid sealed and heat exchanging relationship with respect to each other, a primary cooling fluid conduit system connected to said primary coolin fluid passages of the heat exchanger, an exhaust steam line, a condenser operating under vacuum and connected to said exhaust steam line to receive steam therefrom and condense the same, a pipe system for introducing at least a portion of said condensate from said condenser into one end of the secondary cooling fluid passages of said heat exchanger, a second pipe system connecting the vacuum side of said condenser to the other end of said secondary fluid passages oi the heat exchanger to: reduce the cpressure therein and -.vapor-i-ze'\the nondensate introduced therein thereby cooling the primary'coolingzfluid-passing through saidi heat exchanger; and :an ejector connected in said secondpipe system and' operated by a steam 'line connected thereto to further increase the =vacuurn in saidheat exchanger.

3. In apparatus for cooling a fluid, a heat exchanger raving primary and secondary cooling fliiid passages"therein-in fluid sealed and heat exchanging relationship 1 with respect to each other, a primary coolingfluidconduit system connected to and including'saidprimary cooling fluid passages of the heat exchanger, an exhaust steam line,- a condenser operating under vacuum and connected'to said exhaust steam line to receive steam-therefromandcondense-the same, a pipe system to introduceapredetermined portion of said condensate from said condenser under positive pressure into one end of the secondary cooling fluid passages ofsaid-=heat exchanger, a second pipe system connectingethe vacuum side of said condenser to the'other end of said secondary fluid passages of the heat exchanger to reduce the pressure therein and vaporize the condensate thereby cooling theprimarycooling-fluidpassing through saidheat exchanger; anejector connected in said second-pipe system-and-operated by a steam line connected thereto to further increase the vacuum in'said heat-exchangenand means selectively operable at will to out said ejector in and out of said second pipe system as-desiredr- 4. In apparatusfon cooling-afluid, a heat exchanger having'primaryand secondary cooling fluid passages therein inafluidsealed and heat exchanging relationship, Withrespect to each other, a primary cooling-fluid conduit system connected toand including -saidprimary cooling fluid passages of the heat exchanger, an exhaust steam'line, a condenser operating under vacuum and connected to saidrexhaust steam line to receive steam therefrom andncondense the same, a pipe system including-a pump operable to introduce -a predetermined portion of said condensatefrom said condenser under positive pressure into one end of the secondary cooling fluid passages of said heat exchanger, means to regulate andcontrol the amount of condensate introduced intosaid heat exchanger, and-a second pipe system connecting the vacuum-side of said condenser to the other end of said secondary fluid passages of the heat exchanger to reduce the pressure therein and vaporize the condensate thereby cooling the primary cooling fluid passing through said heat exchanger;

5. In apparatus for cooling a fluid, a heat exchanger having primary and secondary cooling fluid passages therein influid sealed and heat exchanging relationship with respect to each other, a primary cooling fluid conduit system connected to and including said primary cooling fluid passages of-the heat exchanger, an exhaust steam line, a'condenser operating under vacuum and connected to said exhaust steam line to receive steam-therefrom andcondense the same, a pipe system including a pump operable to introduce a predetermined portion of said condensate from said condenser under positive pres sure into one end of the secondary cooling fluid passages of said heat exchanger, means to regulate and control the amount of condensate ntroduced into saidheat exchanger, a second pipe system connecting the vacuum side of said condenser to the other end of said secondary fluid passages of the heat exchanger to reduce the pressure therein and vaporize the condensate thereby cooling the primary cooling fluid passing through said heat exchanger, and an ejector connected in said second pipe system and operated by a steam line connected thereto to further increase the vacuum in said heat exchanger.

6. In apparatus for cooling a fluid, a heat ex-' changer having primary and secondary cooling fluid passages therein in fluid sealed and heat exchanging relationship with respect to each other, a primary cooling fluid conduit system connected to and including said primary cooling fluid passages of the heat exchanger, an exhaust steam line, a condenser operating under vacuum and connected to said exhaust steam line to receive steam therefrom and condense the same, a pipe system including a pump operable to introduce a predetermined portion of said condensate from said condenser under positive pressure into one end of the secondary cooling fluid passages of said heat exchanger, means to regulate andcontrol the amount of condensate introduced into said heat exchanger, a second pipe system connecting the vacuum side of said condenser to the other end of said secondary fluid passages of the heat exchanger to reduce the pressure therein and vaporize the condensate thereby cooling the primary cooling fluid passing through said heat exchanger, an ejector connected in said second pipe system and operated by a steam line connected thereto to further increase the vacuum in said heat exchanger, and means selectively operable at will to out said ejector in and out of said second pipe system as desired' FRANK C. SIMONDS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,954,949 Roe Apr, 17, 1934 2,045,999 Roe June 30, 1936 2,088,382 Miller July 27, 1937 2,088,390 Stalcup July 2'7, 1937 2,112,733 Burnham Mar. 29, 1938 

